ROG STRIX B250F GAMING motherboard for Eth mining

Hi,

I am trying to setup a 6 GPU Rig. I am using ROG STRIX B250F GAMING motherboard. I have been successful in connecting 4 RX 480 8gb OC Sapphire onto it. But as soon as i go over that, it starts showing errors.

Has anyone been using this board . I was facing Code 12 issue earlier. then driver crashed.

Specs

ROG STRIX B250F GAMING
Sapphire RX 480 OC 8GB (4 as of now, want to connect 6)
8GB DDR4
G4400 3.3 GHz Dual Core CPU
Win 10 Pro 64 bit

Please suggest what should i do to get all 6 GPU working.

Regards
Chirash